I use a Pickl-It system, which is a hermetically sealed Fido jar with an airlock. It's comparable to a crock bc it is air-tight, yet it is see-thru.

I shred my cabbage thread-fine on a mandolin and then smash it down really tightly in the Fido. Add a little water and 3 or 4 tbsp salt, put inside a dark cabinet, and in a few weeks, the crispest, tastiest, most awesome thread-texture sauerkraut you'll find!